Climate Change and Human Mobility: The Securitisation Paradigm
The phenomenon of climate change symbolises one of the most pressing multi-dimensional challenges of the 21st century (Tavares Da Costa et al., 2023). Accelerating global environmental degradation manifests through both rapid-onset climate shocks—such as intense tropical cyclones, severe flash flooding, and catastrophic wildfires—and slow-onset environmental disruptions, including sea-level rise, ocean acidification, coastal erosion, desertification, and protracted droughts (Chesler, 2024; Tavares Da Costa et al., 2023). These environmental transformations do not occur in a socio-political vacuum; rather, they interact directly with pre-existing political vulnerabilities, socio-economic inequalities, weak governance structures, and resource dependencies across developing regions. The resulting conditions of acute food and water scarcity, physical unsafety, widespread destruction of critical infrastructure, livelihood collapse, and economic repression have contributed to growing patterns of human displacement and regional migration flows (Chesler, 2024; Tavares Da Costa et al., 2023).
As global environmental shifts severely disrupt agrarian economies and urban settlement viability across the Global South, traditional analytical distinctions between voluntary economic migrants and involuntary asylum seekers have grown increasingly blurred and insufficient. Consequently, these alarming changes in the global sociopolitical landscape have compelled national governments around the world to integrate climate change, environmental stress, and human mobility directly into their national security agendas, systematically expanding military roles into border control operations (Chesler, 2024; McDonald, 2025).
This paradigm shift represents a fundamental conceptual transition in global governance: the re-framing of environmental displacement from a humanitarian crisis requiring international solidarity into an existential national security threat demanding military enforcement and sovereign deterrence (McDonald, 2025; Parker, 2022). Military involvement is particularly evident in the strategic operational frameworks adopted by national security institutions to respond to the projected upsurge of climate-induced human displacement and manage maritime border control operations (McDonald, 2025; Parker, 2022). By operationalising border enforcement through a military lens, sovereign states prioritise territorial integrity, national sovereignty, and physical defense above universal human rights protections, systematically framing asylum seekers and displaced populations as existential security threats to domestic stability, public order, and social cohesion (Hodge, 2015).
This security-focused agenda is prominently reflected in Australia’s aggressive maritime migration policy, known as “Operation Sovereign Borders” (OSB), which was explicitly established to prevent and deter unauthorized maritime arrivals of asylum seekers (ASRC, 2013). Operation Sovereign Borders was established in September 2013 by Prime Minister Tony Abbott as a military-led, multi-agency border security initiative operating under the administrative and operational control of a three-star ADF lieutenant general within the Department of Defence and the Australian Border Force (Hodge, 2015; Huynh, 2023). OSB’s core operational mechanisms combined forceful boat turnbacks and offshore vessel interception, extraterritorial offshore processing in developing Pacific island jurisdictions such as the Republic of Nauru and Papua New Guinea’s Manus Island, and the restrictive granting of temporary protection visas to ensure that incoming asylum seekers were permanently denied settlement rights in Australia (ASRC, 2013; Huynh, 2023).
To justify and sustain these extraordinary executive measures, the Australian government deployed a strategic framing agenda that heavily utilized military terminology and the language of warfare, actively depicting asylum seekers not as vulnerable victims of persecution or environmental disaster, but as illegal infiltrators, sovereign threats, and strategic adversaries (Hodge, 2015).
This militarised border security architecture intersects directly with the worsening environmental crisis across the Indo-Pacific region, where escalating frequencies of extreme weather events, thermal ocean expansion, and rising sea levels are threatening the territorial integrity, freshwater security, and long-term habitability of low-lying island nations (Parker, 2020; Parker, 2022). As environmental degradation forces vulnerable island populations from their homelands, growing numbers of displaced people are seeking refuge and resettlement in regional centers such as Australia.
However, Australia’s rigid border security posture suggests that emerging flows of environmental refugees could face similar punitive deterrence measures, sovereign maritime interception, and administrative rejection rather than legal recognition or humanitarian asylum (McDonald, 2025; Parker, 2020).
Theoretical Foundations: Securitisation Theory and Environmental Displacement
To fully comprehend the operational logic, political durability, and societal acceptance of militarised border responses like Operation Sovereign Borders, it is necessary to examine the theoretical frameworks governing state responses to human mobility. According to the Copenhagen School of security studies, securitisation occurs when a political actor uses a discursive “speech act” to frame a specific issue, social phenomenon, or group of people as an existential threat to a designated referent object—typically the sovereign state, physical territory, or dominant cultural identity (Hodge, 2015; McDonald, 2025). By successfully persuading the public and political elites that an issue poses an imminent existential danger, political leadership gains the moral and legal authority to bypass standard democratic deliberation, suspend conventional civil liberties, and deploy extraordinary emergency measures, such as military border deployment, maritime blockades, and indefinite administrative detention (Hodge, 2015).
In the context of climate-induced human displacement, securitisation operates by converting ecological vulnerabilities into external strategic hazards (McDonald, 2025; Parker, 2022). Rather than framing environmental displacement as a systemic failure of global carbon mitigation or a collective international governance responsibility requiring climate justice and development aid, states adopt an isolationist “fortress” mentality. Under this model, state border infrastructure is conceptualised as a defensive shield designed to protect domestic resources, welfare systems, public infrastructure, and social harmony from external destabilisation (Chesler, 2024; Huynh, 2023). Displaced persons are stripped of their human agency, individual narratives, and socio-historical context; instead, they are discursively transformed into statistical abstractions, “waves,” or demographic pressures capable of overwhelming state capacity and social order (Hodge, 2015).
This securitised narrative relies heavily on the criminalisation of mobility modes. By conflating irregular maritime entry with criminal acts, sovereign incursions, and transnational security risks, governments justify the total militarisation of civil maritime borders (ASRC, 2013; Hodge, 2015). In the case of Australia, this discursive strategy allowed the state to frame boat turnbacks not as a violation of international humanitarian norms, but as a lawful defense of maritime sovereignty and national self-determination (Hodge, 2015; Huynh, 2023). Consequently, human security—defined as individual protection from physical violence, environmental harm, economic starvation, and state persecution—is systematically subordinated to traditional state-centric security, laying the groundwork for severe legal, ethical, and geopolitical contradictions.
Competing Perspectives on Operation Sovereign Borders
Strategic and Operational Arguments: Deterrence, Efficiency, and Equity
Proponents of Operation Sovereign Borders argue that the policy achieved unprecedented strategic effectiveness and demonstrated the utility of decisive state power in managing irregular maritime boundaries (Huynh, 2023; Wood, 2026). Advocates emphasize that a military-led command structure was necessary to systematically dismantle the established business model of transnational human-smuggling syndicates that operated with virtual impunity across Southeast Asia (Huynh, 2023). Following a dramatic surge in unauthorised maritime arrivals between 2008 and 2012—during which over 50,000 individuals arrived via irregular sea routes on hundreds of unseaworthy vessels—the implementation of OSB’s uncompromising deterrence posture brought irregular vessel crossings to a near-total halt (Huynh, 2023; Wood, 2026). Official government records indicate that while hundreds of boats attempted the crossing in peak years, only a single unauthorised maritime vessel reached the Australian mainland in 2014, with zero successful vessel arrivals reported for nearly a decade thereafter (Wood, 2026).
From an operational and financial standpoint, supporters maintain that this total reduction in irregular maritime traffic allowed the Australian Defence Force (ADF) and Australian Border Force (ABF) to optimize resource allocation (Huynh, 2023). By ending the requirement for continuous, emergency maritime search-and-rescue and interception operations across thousands of square nautical miles of the Indian Ocean, naval assets and coastal patrol units could be redeployed toward core national security priorities, regional stability missions, and strategic maritime domain awareness (Huynh, 2023; Parker, 2020). Proponents argue that despite the high initial capital outlay for offshore processing facilities on Nauru and Manus Island, the elimination of ongoing maritime rescue missions and domestic processing bottlenecks produced significant long-term operational savings for the national defense and border protection budgets (Huynh, 2023).
Furthermore, defenders of OSB frame the policy as a humanitarian imperative centered on life-saving deterrence (Huynh, 2023; Wood, 2026). Between 2008 and 2013, when maritime turnback policies were inactive, an estimated 1,200 asylum seekers drowned at sea in hazardous, unseaworthy vessels managed by predatory people smugglers (Wood, 2026). By establishing a strict, predictable policy of zero maritime admittance, OSB removed the financial and practical incentive for vulnerable individuals to undertake life-threatening ocean voyages, resulting in zero recorded maritime drownings in Australian waters in the years following its implementation (Huynh, 2023; Wood, 2026).
In addition to safety arguments, proponents contend that military border enforcement restores procedural equity and fairness to the national immigration framework (Huynh, 2023). Uncontrolled maritime entry allows wealthier asylum seekers who possess the financial capital to pay transnational human smugglers to circumvent official humanitarian channels, effectively jumping ahead of millions of destitute, vulnerable refugees residing in overseas UNHCR camps who lack the financial means for illegal transit (Huynh, 2023). By closing the irregular maritime pathway, Australia restored integrity to its structured offshore humanitarian intake program.
Finally, supporters argue that rigid border enforcement preserves domestic social cohesion, political stability, and public confidence in legal immigration channels (Huynh, 2023; Wood, 2026). By demonstrating total state control over national borders, the policy neutralised populist anti-immigrant sentiment and prevented the political radicalisation and social polarization observed in European nations struggling with unregulated migration crises (Huynh, 2023). This restored confidence is reflected in longitudinal public opinion data. While 78 percent of Australians expressed extreme anxiety regarding unauthorised boat arrivals in 2010, the proportion of voters viewing asylum seekers as a critical election issue dropped by more than half by 2022 (Wood, 2026). Survey data from Ipsos indicates that domestic sentiment softened so significantly under secure border settings that 57 percent of Australians now believe refugees make a positive social and economic contribution, three in four support a universal right to asylum, and Australia successfully accepted three times as many legal humanitarian claims in 2023 than it did in 2013 (Wood, 2026).
Legal, Human Rights, and Diplomatic Criticisms: The Costs of Securitisation
Conversely, legal scholars, human rights organisations, and diplomatic observers vigorously contest the claims of effectiveness and condemn the ethical premises of Operation Sovereign Borders (Amnesty International, 2021; Huynh, 2023). Opponents contend that state sovereignty cannot be exercised in a legal vacuum and that valid national security objectives must remain strictly constrained by international treaty obligations, customary international law, and fundamental human rights norms (Huynh, 2023). Under Article 31 of the 1951 Refugee Convention—to which Australia is a signatory state—governments are explicitly prohibited from imposing penal sanctions on refugees on account of their illegal entry or presence, recognizing that victims of persecution and disaster are frequently forced to cross borders without formal documentation or prior authorization (Amnesty International, 2021; Hodge, 2015). OSB fundamentally breached this legal principle by institutionalising a blanket criminalisation strategy that treated asylum seekers as guilty lawbreakers subject to mandatory offshore detention and administrative banishment (Hodge, 2015).
A critical legal condemnation of OSB centers on Australia’s violation of the customary international law principle of non-refoulement, codified under Article 33 of the Refugee Convention and international human rights law (Amnesty International, 2021). Non-refoulement strictly forbids states from expelling, returning (“refouling”), or transferring any individual to a territory where they would face torture, cruel treatment, or threats to their life and freedom (Amnesty International, 2021). By conducting swift high-seas turnbacks and orange-lifeboat transfers without conducting individualized refugee status determinations, legal representation, or vulnerability assessments, Australian maritime forces risked returning asylum seekers directly to persecution or indirect chain-refoulement through third countries (Amnesty International, 2021; Huynh, 2023).
Furthermore, human rights monitoring bodies, including Amnesty International (2021), documented extensive breaches of the UN Protocol Against the Smuggling of Migrants by Sea. Australian authorities subjected intercepted asylum seekers to arbitrary at-sea detention, denied access to legal counsel and independent medical assessments, and subjected detainees to inhumane and degrading treatment (Amnesty International, 2021). In offshore processing centers on Nauru and Manus Island, conditions were described by international observers as amounting to systemic institutional abuse and psychological torture (Amnesty International, 2021; Huynh, 2023). Between 2012 and 2021, the average duration an individual spent in Australian immigration detention reached an unprecedented global record of 627 days, culminating in severe psychiatric trauma, widespread self-harm, and multiple preventable deaths (Huynh, 2023).
Diplomatically, critics argue that OSB’s isolationist framework severely damaged Australia’s international standing and eroded regional cooperation across the Indo-Pacific (ASRC, 2013; Huynh, 2023). Rather than contributing to regional burden-sharing or resolving the root causes of forced migration, Australia unilaterally shifted its humanitarian obligations onto economically vulnerable neighboring states (Wood, 2026). Maritime turnback operations provoked recurring diplomatic friction with Indonesia, whose government repeatedly condemned Australian naval incursions into its territorial waters as overt violations of national sovereignty (ASRC, 2013; Huynh, 2023). Moreover, by establishing a precedent of militarised rejection, Australia undermined international norms governing refugee protection, providing autocratic regimes worldwide with a legal and operational pretext to justify their own border closures, pushbacks, and forced returns (Huynh, 2023).
Climate Securitisation and Regional Realities in the Indo-Pacific
The intersection of climate change, human mobility, and militarised border architecture presents a severe governance challenge for the Indo-Pacific region (McDonald, 2025; Parker, 2020). The Pacific region contains several low-lying atoll nations—most notably Tuvalu, Kiribati, and the Marshall Islands—where the maximum land elevation rarely exceeds two to three meters above sea level (Parker, 2020; Parker, 2022). Comprehensive climate projections indicate that accelerating sea-level rise, combined with saltwater intrusion into freshwater lens aquifers, coastal erosion, and agricultural soil salinisation, will render significant portions of these island territories physically uninhabitable decades before complete submersion occurs (Parker, 2020).
Under current international legal definitions, individuals displaced primarily by environmental degradation or climate disasters do not meet the criteria for “refugee” status under the 1951 Refugee Convention, which strictly requires a well-founded fear of persecution based on race, religion, nationality, membership of a particular social group, or political opinion (McDonald, 2025). This institutional gap creates a legal normative vacuum: climate-displaced individuals face existential threats to their survival, yet possess no legally binding right to cross international borders, claim asylum, or demand protection in neighboring developed states (McDonald, 2025; Parker, 2022).
If regional middle powers like Australia continue to rely exclusively on militarised deterrence frameworks modeled after Operation Sovereign Borders, climate-induced displacement in the Pacific will inevitably trigger humanitarian crises and regional instability (McDonald, 2025; Parker, 2020). Applying naval turnbacks, offshore interception, and administrative detention to populations whose homelands are rendered uninhabitable by global greenhouse gas emissions represents a profound moral contradiction (McDonald, 2025). Australia’s high per capita carbon footprint and historical resource extraction position it as a major contributor to regional environmental change, while small island developing states contribute minimally to global emissions yet endure its most immediate consequences (Parker, 2022). Refusing entry to climate-displaced Pacific neighbors through military deterrence risks damaging Australia’s strategic partnerships in the region, creating geopolitical openings for competing major powers—such as China—to expand their diplomatic, economic, and security influence across the Pacific by offering climate adaptation assistance and development finance (Parker, 2020; Parker, 2022).
Rethinking Governance: Beyond Securitisation Toward Cooperative Mobility
Addressing the crisis of climate-induced displacement requires moving beyond pure militarisation toward comprehensive, regional mobility frameworks based on human security, international solidarity, and proactive adaptation (McDonald, 2025; Wood, 2026). Military border operations treat the symptoms of human mobility while ignoring its underlying environmental, economic, and structural drivers (Chesler, 2024; McDonald, 2025). To establish a sustainable, long-term policy response, middle powers must replace punitive deterrence architectures with legal pathways, managed labor mobility schemes, and international burden-sharing mechanisms (McDonald, 2025; Wood, 2026).
An exemplary step toward progressive climate mobility governance is reflected in bilateral initiatives such as the Australia-Tuvalu Falepili Union treaty (Wood, 2026). Signed in late 2023, this historic agreement establishes a dedicated visa pathway allowing Tuvaluan citizens to live, study, and work in Australia, providing a dignified adaptation pathway for islanders facing environmental displacement without requiring them to rely on irregular maritime routes or apply for traditional refugee status (Wood, 2026). Expanding similar bilateral and multilateral mobility agreements across the Pacific represents a constructive alternative to the securitisation framework, converting forced migration into managed, dignified mobility (McDonald, 2025; Wood, 2026).
Furthermore, regional security strategies must integrate environmental protection and climate resilience directly into defense planning (McDonald, 2025; Parker, 2022). Rather than framing military forces primarily as border enforcement agents tasked with repelling displaced populations, defense capabilities should be oriented toward disaster relief, humanitarian assistance, climate resilience building, and maritime domain awareness across the Indo-Pacific (McDonald, 2025; Parker, 2022). Investing in climate adaptation infrastructure, renewable energy systems, and coastal defense mechanisms within vulnerable Pacific nations helps build local resilience, allowing communities to remain in their ancestral homelands for as long as possible (Parker, 2020; Parker, 2022).
Conclusion
Australia’s Operation Sovereign Borders demonstrates clear contradictions regarding the morality, strategic sustainability, and long-term effectiveness of climate securitisation (Hodge, 2015; Huynh, 2023). While the military-led operation successfully prevented the arrival of irregular vessels and asylum seekers, thereby virtually eliminating maritime mortalities in Australian waters, it achieved these operational metrics by compromising international law, human rights, and regional diplomatic cooperation (Amnesty International, 2021; Huynh, 2023; Wood, 2026).
As climate change continues to degrade environmental stability, destroy agrarian livelihoods, and threaten territorial habitability across the Indo-Pacific, the volume of vulnerable displaced populations will inevitably expand (Chesler, 2024; McDonald, 2025). Replicating punitive military deterrence operations against environmental refugees represents a shortsighted, financially burdensome, and ethically tenuous strategy that undermines multilateral diplomatic trust and regional stability (McDonald, 2025; Parker, 2020). Ultimately, the fundamental question facing national policymakers is whether isolationist border enforcement can remain viable in an increasingly volatile world, or whether enduring regional security requires replacing militarised border architectures with targeted climate adaptation funding, cooperative regional governance, dignified legal migration pathways, and international climate justice (McDonald, 2025; Wood, 2026).Australia’s Operation Sovereign Borders demonstrates clear contradictions regarding the morality, strategic sustainability, and long-term effectiveness of climate securitisation (Hodge, 2015; Huynh, 2023). While the military-led operation successfully prevented the arrival of irregular vessels and asylum seekers, thereby virtually eliminating maritime mortalities in Australian waters, it achieved these operational metrics by compromising international law, human rights, and regional diplomatic cooperation (Amnesty International, 2021; Huynh, 2023; Wood, 2026).
References
ASRC (2013). Operation Sovereign Borders. /api/wp-media/2013/07/Operation-Sovereign-Borders-May-2014.pdf
Chesler, A. (2024). Environmental displacement and political instability: Evidence from Africa. Journal of Peace Research, 62(4), 1076–1094. https://doi.org/10.1177/00223433241274979
Kim Huynh. (2023, September 18). Looking back on a decade of Operation Sovereign Borders: Should we still “stop the boats”? ABC Religion & Ethics. https://www.abc.net.au/religion/looking-back-on-a-decade-of-operation-sovereign-borders/102833780
McDonald, M. (2025). Defence and climate change: An introduction. Contemporary Security Policy, 47(1), 9–25. https://doi.org/10.1080/13523260.2025.2583233
Hodge, P. (2015). A grievable life? The criminalisation and securing of asylum seeker bodies in the ‘violent frames’ of Australia’s operation sovereign borders. Geoforum; Journal of Physical, Human, and Regional Geosciences, 58, 122–131. https://doi.org/https://doi.org/10.1016j.geoforum.2014.11.006
Parker, R. (2020). Is Australia’s defence policy right for the times? Security Challenges, 16(2), 34–46. Is Australia’s Defence Policy Right for the Times?
Parker, E. (2022). Climate and Australia’s national security. The Forge. 16 November. https://theforge.defence.gov.au/article/climate-and-australias-national-security.
Tavares Da Costa, R., Krausmann, E., Hadjisavvas, C. (2023). Impacts of climate change on defence-related critical energy infrastructure. Publications Office of the European Union. https://doi.org/10.2760/03454
